Electroreductive deposition of polymeric coatings having RuII redox centers on Pt, Pd and sintered Fe-(5-10)%Ni electrodes

Pt, Pd and sintered Fe-(5-10)%Ni electrodes were coated by reductive electrodeposition of electrochemically generated trans-[RuCl2(vpy)(4)]-based films (vpy = 4-vinylpyridine). The complex trans-[RuCl2(vpy)(4)] was synthesized from a ruthenium blue solution and characterized by various techniques including electronic spectroscopy (446 nm), FTIR, H-1 and C-13 NMR elemental analysis and cyclic voltammetry (E-1/2 = -103.5 mV cs. Ag-Ag+). The results obtained confirmed the proposed structure of the monomer. Electrochemical studies carried out on films generated by either a potentiostatic or a galvanostatic approach revealed that the redox properties of poly-trans-[RuCl2(vpy)(4)] were similar to those of the monomer in solution. The morphology of the films was investigated by scanning electron microscopy (SEM). Microprobe X-ray dispersive energy analysis (EDS) was also performed on the polymer surface. The feasibility of film formation on Fe-5%Ni and Fe-10%Ni sintered electrodes has been demonstrated.